What was a key challenge faced by the united states during world war 2 A. fighting the war on several fronts ( asia and europe)
B. lack of public support for the war effort
C. total reliance on naval power
D. difficulty gaining congressional support​

answer: karl marx, max weber, and emile durkheim (the fourth could be considered georg simmel)

explanation:

in 1862, president lincoln's emancipation proclamation opened the door for african americans to enlist in the union army. although many had wanted to join the war effort earlier, they were prohibited from enlisting by a federal law dating back to 1792.

explanation:

during world war ii